Attention has been focused recently on nucleic acid medicines such as synthetic double-stranded RNA such as poly(I)●poly(C), short interfering RNA (siRNA) utilizing RNA interference (RNAi), microRNA (miRNA), short hairpin RNA (shRNA), antisense DNA and antisense RNA, which have been actively investigated. Among the nucleic acid medicines, nucleic acid medicines like siRNA are hardly delivered to a tissue with a lesion even when the medicines are administered independently and systemically from for example a vein. Therefore, it is needed to administer such nucleic acid medicines after given treatments such as allowing an appropriate carrier to include the nucleic acid medicines for administration or administering the nucleic acid medicines topically to a tissue with a lesion.
The carrier for delivering such nucleic acid medicines to a tissue with a lesion includes for example cationic liposomes such as LIPOFECTIN (under trade mark), LIPOFECTOAMINE 2000 (under trade mark) and OLIGOFECTOAMINE (under trade mark) and cationic liposomes (hereinafter, referred to as “Compound A liposome”) containing 2-O-(2-diethylaminoethyl)carbamoyl-1,3-O-dioleoylglycerol (hereinafter, referred to as “Compound A”) and a phospholipid as the essential components (see for example WO 94/19314). Since these cationic liposomes likely accumulate readily in liver and spleen when administered systemically from for example a vein, it is expected to apply the cationic liposomes as therapeutic agents of liver cancer and hepatitis by allowing the cationic liposomes to include nucleic acid medicines. It is actually reported that complexes of Compound A liposome with for example synthetic double-stranded RNA such as poly(I)●poly (C) are effective for the treatment of liver cancer and hepatitis (see for example WO 99/20283, WO 99/48531, Kazuko Hirabayashi, et al., Cancer Research, 1999, Vol. 59, p. 4325-4333, and Kazuko Hirabayashi, et al., Oncology Research, 1999, Vol. 11, p. 497-504).